Yang posted online comments critical of local police over their handling of the death of a karaoke bar manager, whose body was found lying on a road on Thursday morning. Photo: Bloomberg

A teenager from rural Gansu province who became the first person on the mainland to be detained under controversial new internet defamation rules lives in a 100-square-foot rented room with his grandparents, said a lawyer who has volunteered to defend the youth.

His parents were away working in Beijing, so like millions of other children across the country he was cared for by his grandparents, said the lawyer, You Feizhou.

The old couple and the boy moved to Zhangjiachuan county's main town from the countryside so the boy could attend school.

The case of the boy, who can only be identified by his surname Yang, aroused national attention when he became first person detained since a judicial interpretation was issued last week that allowed the jailing of anyone who made defamatory comments online that were reposted at least 500 times.

Yang posted comments critical of local police over their handling of the death of a karaoke bar manager, whose body was found lying on a road on Thursday morning.

You, from Chongqing, and Wang Shihua, from Beijing, have volunteered to defend Yang and arrived in Zhangjiachuan yesterday.

In his microblog, You depicted the boy and his grandparent's home as "simple and crude - without a toilet or kitchen".

The two lawyers agreed that helping Yang return to school as soon as possible was their top priority.

Yang's father, Yang Niuhu, told the Beijing News that his son was outgoing and bore no hatred to society.

He wrote posts because of his sense of justice, the father said.

The son previously attended school in Beijing where his father worked but moved back to his hometown to sit college entrance examinations, as required, the father said.

Yang made three posts about police handling of the death of the karaoke bar manager. Public security officials conducted an autopsy and said he died from head injuries after jumping from a building.

Yang wrote that he had heard a different account of the death from the man's family - that said he had been beaten up before dying - and accused the police of failing to properly investigate the incident. He also called for a protest over the matter.

Local police detained Yang on charges of "picking quarrels and provoking trouble".

You said the influence of Yang's posts was negligible, since his posts were seldom read or forwarded.

Neither were his posts about the manager's death read more than 5,000 times or shared more than 500 times, two thresholds established by the recent judicial interpretation that could lead to the jailing of an offender.

This article appeared in the South China Morning Post print edition as Net defamation teen from very humble home